In connection with hospitalizations for various illnesses or conditions, one of the most prominent causes for discomfort or unpleasantness and in some cases, also of injury and possible infection, is the repeated necessity for taking blood samples, for administering intravenous feeding and for injections of various medicines or drugs into the bloodstream by means of a hypodermic needle. For many persons, the veins are relatively prominent and accessible, but in a substantial percentage of patients, especially those who are overweight, the blood vessels are difficult to locate and repeated attempts are required to strike the vein or artery. Furthermore, it is often necessary to repeat such procedures several times a day for days or weeks in succession. Some patients in such circumstances suffer serious consequences such as bruised and swollen arms and inflamed blood vessels which do not recover until weeks after such injury has been sustained. In some cases, the patient suffers severe emotional trauma during and also in anticipation of such procedures, and the trauma can interfere with the patient's recovery from his illness.
There is therefore an important need for improved devices and techniques for such procedures of this nature which will eliminate or significantly reduce the associated discomfort and injury.